Answer
$\ln (10)$
Work Step by Step
We are given that $I=\int_0^9 \dfrac{1}{x+1} \ dx$
In order to solve the above integral, we will use the following formula such as:
$\int x^n \ dx=\dfrac{x^{n+1}}{n+1}+C$
Now, we have
$I=\int_0^9 \dfrac{1}{x+1} \ dx$
or, $=[\ln |x+1|]_0^9$
or, $=[\ln |9+1|]-[\ln |0+1|]$
or, $=\ln (10)$
